Dry type printer-developer apparatus



April 26, 1960 0, TRUMP 2,933,997

DRY TYPE PRINTER-DEVELOPER APPARATUS Original Filed Jan. 16, 1956 FlC3-l.

INVENTOR FREDERICK O. TRLJM P BY r z/ ATTORNEYS UnitedStates Patent V "2,953,997. in ND-RYTYPE PRINTERQDEVELOPER APPARATUS Frederick 0. Trump, West Springfield, Mass., assignor to Iecnifax Corporation, Holyoke, Mass., a corporation of Massachusetts original application January 16 1956, Serial No. 559,195.

T hisinvention relates to improvements in printerdevelopermachines for producing a dry type white-print. Machines of this general character are adapted to'print and then 'develop sheets of sensitized material through exposure to. the gases of ammonia and the like. Com-' monlysuch machines are known as diazo-type developers si ce paper sheets coated with diazo-type compounds are often most. generally utilized in obtaining prints from the machine. Many other specialty compounds and materials are used, however, and sensitized layers or sheets having extremely delicate emulsion surfaces may be passed through such machines for development of printed matter of various types. y

. fl'his a divisional application of my application Serial .No..559,l95,.filed January 16, 1956, now Patent Number 2,87.8,742,; i n which the developer tank used in the machine of this invention is fully disclosed and claimed. ,7

is the primary object of the invention to provide a typeprinting machine of an extremely compact over- ;size with atank of greatly increased developing area and inwhichthe speed of the printing and developing operations may be synchronized.

Another object is to make provision in a machine of this character for stacking the developed sheets at the exit end thereof with the printed matter facing upwardly and accessible to the operator at the front of the machine with the tail edges evenly piled. This object is accomplished-without unduly complicating the conveyor belt apparatus. at the delivery end of the apparatus.

Qther objects and advantages of the invention will be seenfrom the following disclosure of. an embodiment thereof.

in the drawings :J..F 8-.-1 is a vertical section of a machine embodying the invention;

Fig; 2 is anenlargedview of the developing tank unit shown in the assembly of Fig. 1-; a

,- .,;F,ig. 3,i's a fragmentary magnified detail view of a per- ::.forated liner or screen member which forms one side of :the developing zone of the tank assembly shown by Fig.

2;.and- Big. 14 shows an alternativeform of tank'assembly.

copies are to be madebythe machine, A stacking tray ra'tus for stacking the printed sensitized sheets as they are received from'the developing mechanism. The trays [and 4 and the shield 6 across the front side of the delivery' belt'system at the e'xitend. of the developer conceal the operative mechanism friom view atjthe front sidc. of the housing. As will be readily understood the vari- Divided and this application May 20, 1958, Serial No.

ous parts of the mechanism are supported between the sidewalls 7 of the housing in suitable bearing andmounting structure (not shown). Conventional motor drives (also not shown) for the belt assemblies as will be described are preferably located in the lower section of the housing. The housing is adapted to rest on the floor with thetop thereof at a height of approximately six feet so that the trays and feeding station are located at a convenient operator working level.

At the entrance end 2 of the apparatus a continuous web of sensitized material or, as is more often the case, a series of sensitized sheets may be fed between a perforated conveyor'belt 10 and an auxiliary conveyor belt 11. Atracing or the master sheet bearing printed matter for reproduction is superimposed on the sensitized surface of the copy sheet which is facing upwardly and is conveyed along with the sensitized sheet between the belts. As shown, the auxiliary belt 11 is endless, being driven by the roller 12 and wrapped around the end of a tension sheet 13, an idler roll being indicated at 12.

-The feeding run of the printing belt 10 is directed from the entrance 2 upwardly to the lower side of a rotatably mounted printing cylinder 14 of conventional glass'construction having a lamp shown at 15. The belt is tensioned around the cylinder for approximately 180, and then directed forwardly in the housing and upwardly toward the entrance end of the developer mechanism. Along the delivery portion of the belt 10 from the cylinder 14 to the take off end is a suction tank 16 which maintains the sensitized sheets against the underside of belt 10 for delivery to the developer. A pick-off assembly for stripping the master sheet or tracing from the cylinder 14 is shown at 17 for depositing the originals on the tracing stacking tray 3. The driving roller for belt 10 is shown at 18 with the series of rollers for travel of the same being designated by numeral 18'. V

The sensitized sheets are carried by belt 10 into contact with a delivery belt 20 which is tensioned against the belt 10-as it reverses its direction around the end roller 18. A guide at 21 serves to direct the sensitized sheet at the entrance between the belts 10 and 20 and a pickotf member is shown at 22 to insure separation. of a sheet from belt 10 to guide it against belt 20 to the entrance end of a blanket or sealing sleeve 30. of the developer.

The delivery belt 20 is drivenby a cylinder or roller 23. inwardly of the housing the belt is turned on roller 23 and upwardly thereof a tensioning member 24 provides an upward delivery run urging belt 20 against belt 10 at the roller 18' as well as against the sealing sleeve 30 and its roller. From the tip of tension member 24, the belt again runs against the sleeve 39 and delivers the developed sheets from the tank to the exit end for 4-accessible from the top ,is at the exit end of the appastacking on tray 4. Belt 20 is upwardly and inwardly directed around the end driving cylinder 31 of the sealing sleeve and reversely around the tip end of a second vertically disposed tensi-oning member at 25.

a The sealing sleeve 30 conveys the printed sheetsa'round the surface of the perforated developing tank 49 and back to the deliveryconveyor beltli) for stacking on the tray 4. i The sleeve 30 is driven by cylinder 31 spacedfromthe exit end of the tank'and by the cylinder 32 adjacent the entrance end. Guide rollers are shown at 33 and tension rollers at 34 on the outer or return run of the sleeve. 'In order to assist in the disposal of developed sheets onto the stacking tray 4 a stacking plate member 35 is provided. At its lower edge the plate serves as pick-off member to prevent a. sheet following sleeve 30 on its return run. At its upper edge o ths ,plate 35 serves as a marginal flange at 36 for the front edge of the tray 4. In this manner the sheets stacked on the tray 4 cannot interfere and block'the lead- Patented Apr. 26, 1960 3 ing edge of a sheet emerging from the developer. A mounting plate at 37 fixed to the underside of tray 4 holds the plate 35 in position.

Referring now to Fig. 2 the tank 40, which is described and claimed in my. copending application Serial No. 559,195 referred to above, is a closed vapor generating tank with heater and tray elements at 41 for evaporating ammonia, for example, as may be fed to the tray in predetermined amounts according to the size of the tank, the speed of development, and material being treated. The tank as shown is preferably elliptical to form a squat compact developing zone. At the entrance and exit ends of sleeve travel around the tank the wall portion as at 42 is imperforate. Over the major portion comprising the remainder of the tank the wall is perforated by closely spaced holes as at 43 for the passage of the developing vapors through to the developing zone. The developing zone is provided around the perforated tank wall by a liner or screen indicated at 44 and the sealing sleeve 3%) blanketing the entire perforated area of the tank.

The screen 44 is suitably afiixed as at 45 to the tank wall portion at 42 adjacent the entrance end and is V positioned to lie against the perforated tank wall with the free end of the screen at 46 extending beyond the adjacent exit and leading from the tank. The end 46 extends to the junction of the sleeve and delivery belt 20 and assists in the transfer of the sensitized sheet to the final delivery belt transfer to the tray 4.

Screen 44 is also perforated and as shown by the magnified fragmentary view of Fig. 3 is provided with a multiplicity of closely spaced holes 47 through which the developing vapors may be admitted to the surface of the sensitized sheet for developing action as the sheet is frictionally advanced by the sleeve 30. The screen 44 is of synthetic plastic material chemically inert to'the vapors and of high heat resistance with self-lubricating qualities to render the surface over which the sheets pass with the sensitized surface in contact therewith ture of at least 180 over which the direction of the path of the sheets can be reversed. Thus the tank may be flattened in form to insure a length of travel in the developing zone adequate to properly expose the sheets to the vapors as well as to reduce the over-all height of the tank.

The tank is preferably elliptical in transverse cross section as shown. Alternatively, the tank may be cylindrical as indicated by the tank 70 of Fig. 4. The tank may also be otherwise defined and it has been found that by providing a surface curvature of at least 180 the sheets can be reversely directed to permit theclosely spaced adjacent relation of entrance and exit paths to and from the tank and the handling of the developed sheets for delivery to the tray 4. The sleeve 71 (Fig. 4) is shown closely spaced at the entrance and exit ends after the manner of sleeve 30 of Fig. 1. A screen 72 is attached to the imperforate wall section as at 73 and a delivery belt at 74 is shown in a similarly disposed relation to the sleeve for delivery of sheets to and from the developing zone of the circular tank.

The screen 44 which faces or lines the outer surface of without dismantling the sleeve 30 from the tank. The

outer surface of the tank might be also otherwise lined as by spraying with a thin film of polytetrafluoroethylene for a permanently affixed type of facing. A sprayed coating may be utilized successfully but it has been found that the removable sheet is preferred not alone for its removability but also because the more closely spaced perforations of the sheet 44 provide a more complete and even diffusion of developing vapors in the zone through which the sheets s'pass between the sheet 44 and sleeve 30. At each opening 47 ofthe sheet vapor emanating from the openings of the tank wall passes through to the developing zone side thereof to spread out over the edges of each opening 47 and produce a halo-like effect around the edges. The haloing effect at each opening intersects the haloes of each adjacent opening to produce the even and complete diffusion of vapors over the entire surface area and eliminates patterning on the background of the sheets being developed. The openings of the sheet 44 are preferably on the order of .020 of an inch in diameter at spacings of .031 of an inch'in a sheet of approximately .010 of an inch. This is in-contrast to the size of the openings in the wall of tank 40 which may be on the order of .1875 of an inch in diameter with a spacing of .250 of an inch.

The polytetrafluoroethylene sheet as previously mentioned is of a non-sticky, chemical and heat resistant character and in particular the surface over which the sheets pass to be developed is of an extremely slippery and self-lubricating nature. It has been discovered that sheets having the most delicate of emulsions may be conveyed. by the sleeve in a reversely turned, path such as that at the end of the tank around the curvature.

It will be noted that not only does the elliptical tank of the preferred form as shown by the drawings utilize the maximum possible developing area of this type of closed vapor generating tank but also it makes'possible provision for a delivery of developed sheets at the front of a machine without an intricate conveyor belt mechanism. The delivery is made furthermore with the printed side of the sheet facing the operator. The trailing or tail end edge of each sheet regardless of the sheet size is always in the same position nearest the operator.

7 It is well recognized in the trade that prior machines of this general type have been objectionable from the standpoint of the mechanics of handling the sheets and delivery for an operators convenience. Many such factors have necessarily been subordinated because of the additional expense involved as well as the problem of increasing the overall size of the machine'with prior conventional tanks which have used only one side of a closed vapor tank.

p In the apparatus as shown by Fig. .1, the developed material as it emerges from the developer is guided by the sleeve 30 and belt 20 to the stacking tray 4 with the coated side of the sheet facing in an upward position in full view of the operator. The tail edge regardless of the size of the sheet will thus always be closest to the operator and permit easy removal in spite of a large size or the stacking of different sizes. 0n conventional machines-as will be recognized, the image faces downwardly and prevents quick observation as to' the quality of the print while the operator is busy feeding material into the machine. Here the operator may observe the condition and clarity of each print as it emerges onto the tray. It may be noted also that the tray extends from the front of-the machine to the rear wall and thus a print of'a size equal to the depth of the housing can be stacked for front face up delivery without adjustment on thepart of the operator. In the event a sheet of greater depth is passed through the machine a kicker belt is provided at the extreme end of the tray 4. This belt shown at 60 on rollers 61 serves by pressure against tray 4 to fric- 'tionally draw long sheets from the cabinet through a slotted port at 62 for deposit on a platform or table (not vshown at the rear of the machine.

In connection with the large developing zone of the new machine it is known that of necessity the developing capacity is dependent on the amount of time the sensitized sheet material may be exposed to the vapors. In the apparatus illustrated where the printing and developing operations are adapted to be synchronized the developing area is of sufiicient size to give development in one pass through the developing zone in most instances. With the introduction of high wattage printing lamps the printing speed has been stepped up from 30 to 100 feet per minute for diazo-type materials yet heretofore no corresponding increase in developing exposure area has taken place without necessitating an increased overall machine size according to the conventional design. It will be seen the new design as disclosed will more than double the developing area for exposure without increasing the size of the machine. The practically negligible or almost zero frictional characteristics of the polytetrafluoroethylene liner surface permits a smooth travel of the sealing sleeve and sensitized sheet while completely avoiding any bind ing action around the 180 or more curvature.

What is claimed is:

1. In a dry type developing machine a cabinet housing having a combined front and top wall access opening, a stacking tray at the top of the cabinet accessible through said opening and a feed board at the lower edge of the opening, a printing cylinder and in vertically spaced relation thereto a closed vapor generating developer tank with a perforated wall area including a curved surface of at least 180 curvature, said cylinder and tank being mounted between the side walls of the housing rearwardly of said opening, an endless conveyor belt tensioned around the said cylinder with end rollers mounted above and below said cylinder forwardly in the housing and the lower roller being adjacent said feed board, a sealing sleeve tensioned around said developer tank blanketing the perforated area thereof with a lower end roller vertically adjacent the upper end roller of the cylinder belt and the upper end roller of the sealing sleeve being positioned forwardly beneath the front edge of said stacking tray, and an endless delivery belt with a portion bridging the adjacent end rollers of the cylinder belt and sleeve and tensioned against the same for delivering sheets from the printer mechanism to the developer tank, said endless delivery belt having another portion thereof tensioned against the sleeve adjacent its exit end and tensioned upwardly around said upper end roller of the sleeve for delivery of sheets from the tank to the stacking tray with the developed image facing upwardly.

2. A dry type printing and developing machine comprising a cabinet, a platform at the front of the machine, a delivery tray also at the front of the machine and above the platform at the top of the machine, a printer spaced rearwardly of said platform, a conveyor means for carrying sensitized material placed face up on said platform to said printer, a developing tank spaced above said printer and spaced at least in part forwardly of said printer, said conveyor means further being ar-' ranged to carry the sensitized material to the forwardrnost portion of said tank and reversing its direction of travel and bringing it into intimate contact with first the bottom and then around the rearmost endof said tank and then forwardly along the top of the tank towards the front of the machine and then upwardly and rearwardly to discharge the sensitized material face up in the delivery tray.

3. A dry type printing and developing machine comprising a cabinet, an infeed platform at the front of the machine, a print delivery tray also at the front of the machine and spaced above the platform at the top of the machine, a master sheet delivery tray at the front of the machine intermediate the platform and the print delivery tray, a printer spaced rearwardly of said platform, a deveioping tank spaced above said printer, conveyor means for carrying sensitized material placed face up on said platform with a master sheet superposed thereon away from said infeed platform, said conveyor means being constrained to carry said sensitized material and master sheet rearwardly from said platform beneath and past said printer and then forwardly of said machine, means for separating the master sheet frorn the sensitized ma terial as they are so moved forwardly and depositing the master sheet in its delivery tray, said conveyor means then being constrained to reverse the direction of travel of said sensitized material towards the rear of the machine and carrying it past said developer, said conveyor means being constrained to thereafter reverse the direction of travel of said sensitized material and carrying it forwardly of said machine, and then again to reverse the direction of travel of said sensitized material and carry it rearwardly and upwardly of said machine to discharge it into said delivery tray with its sensitized or printed surface facing upwardly.

Trump Aug. 9, 1949 Brunk June 16, 1953 

